(a)[3]
Find the probability that the mass of peaches sold on a chosen day lies between $56\text{ kg}$ and $75\text{ kg}$.
(b)[3]
Find $\sigma$.
(c)[1]
Find the probability that, in a randomly selected week, the first day on which less than $59.1\text{ kg}$ of cherries are sold is the fifth day of the week.
(d)[2]
Find the probability that, in a randomly selected week, the first day on which less than $59.1\text{ kg}$ of cherries are sold comes before the fifth day of the week.